#pragma once
// <bit> -*- C++ -*-

// Copyright (C) 2018-2024 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file include/bit
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_BIT
#define _GLIBCXX_BIT 1

#pragma GCC system_header

#if __cplusplus >= 201402L || defined ARDUINO_ARCH_SAM

#include <type_traits>

#if _GLIBCXX_HOSTED || __has_include(<ext/numeric_traits.h>)
#include <ext/numeric_traits.h>
#else
#include <limits>
/// @cond undocumented
namespace __gnu_cxx
{
  template <typename _Tp>
  struct __int_traits
  {
    static constexpr int __digits = std::numeric_limits<_Tp>::digits;
    static constexpr _Tp __max = std::numeric_limits<_Tp>::max();
  };
}
/// @endcond
#endif

#define __glibcxx_want_bit_cast
#define __glibcxx_want_byteswap
#define __glibcxx_want_bitops
#define __glibcxx_want_int_pow2
#define __glibcxx_want_endian
#include <bits/version.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
  _GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   * @defgroup bit_manip Bit manipulation
   * @ingroup numerics
   *
   * Utilities for examining and manipulating individual bits.
   *
   * @{
   */

#ifdef __cpp_lib_bit_cast // C++ >= 20

  /// Create a value of type `To` from the bits of `from`.
  /**
   * @tparam _To   A trivially-copyable type.
   * @param __from A trivially-copyable object of the same size as `_To`.
   * @return       An object of type `_To`.
   * @since C++20
   */
  template <typename _To, typename _From>
  [[nodiscard]]
  constexpr _To
  bit_cast(const _From &__from) noexcept
#ifdef __cpp_concepts
    requires(sizeof(_To) == sizeof(_From)) && is_trivially_copyable_v<_To> && is_trivially_copyable_v<_From>
#endif
  {
    return __builtin_bit_cast(_To, __from);
  }
#endif // __cpp_lib_bit_cast

#ifdef __cpp_lib_byteswap // C++ >= 23

  /// Reverse order of bytes in the object representation of `value`.
  /**
   * @tparam _Tp     An integral type.
   * @param __value  An object of integer type.
   * @return         An object of the same type, with the bytes reversed.
   * @since C++23
   */
  template <integral _Tp>
  [[nodiscard]]
  constexpr _Tp
  byteswap(_Tp __value) noexcept
  {
    if constexpr (sizeof(_Tp) == 1)
      return __value;
#if __cpp_if_consteval >= 202106L && __CHAR_BIT__ == 8
    if !consteval
    {
      if constexpr (sizeof(_Tp) == 2)
        return __builtin_bswap16(__value);
      if constexpr (sizeof(_Tp) == 4)
        return __builtin_bswap32(__value);
      if constexpr (sizeof(_Tp) == 8)
        return __builtin_bswap64(__value);
      if constexpr (sizeof(_Tp) == 16)
#if __has_builtin(__builtin_bswap128)
        return __builtin_bswap128(__value);
#else
        return (__builtin_bswap64(__value >> 64) | (static_cast<_Tp>(__builtin_bswap64(__value)) << 64));
#endif
    }
#endif

    // Fallback implementation that handles even __int24 etc.
    using _Up = typename __make_unsigned<__remove_cv_t<_Tp>>::__type;
    size_t __diff = __CHAR_BIT__ * (sizeof(_Tp) - 1);
    _Up __mask1 = static_cast<unsigned char>(~0);
    _Up __mask2 = __mask1 << __diff;
    _Up __val = __value;
    for (size_t __i = 0; __i < sizeof(_Tp) / 2; ++__i)
    {
      _Up __byte1 = __val & __mask1;
      _Up __byte2 = __val & __mask2;
      __val = (__val ^ __byte1 ^ __byte2 ^ (__byte1 << __diff) ^ (__byte2 >> __diff));
      __mask1 <<= __CHAR_BIT__;
      __mask2 >>= __CHAR_BIT__;
      __diff -= 2 * __CHAR_BIT__;
    }
    return __val;
  }
#endif // __cpp_lib_byteswap

  /// @cond undocumented
#ifdef ARDUINO_ARCH_SAM
  template <typename _Tp>
  constexpr _Tp
  __rotl_1(_Tp __x, int __s, int _Nd, int __r) noexcept
  {
    return __r == 0 ? __x : __r > 0 ? (__x << __r) | (__x >> ((_Nd - __r) % _Nd))
                                    : (__x >> -__r) | (__x << ((_Nd + __r) % _Nd)); // rotr(x, -r)
  }
  template <typename _Tp>
  constexpr _Tp
  __rotl_0(_Tp __x, int __s, int _Nd) noexcept
  {
    return (_Nd & (_Nd - 1)) == 0 ?
                                  // Variant for power of two _Nd which the compiler can
                                  // easily pattern match.
               (__x << (__s % _Nd)) | (__x >> ((-__s) % _Nd))
                                  : __rotl_1(__x, __s, _Nd, __s % _Nd);
  }
  template <typename _Tp>
  constexpr _Tp
  __rotl(_Tp __x, int __s) noexcept
  {
    return __rotl_0(__x, __s, __gnu_cxx::__int_traits<_Tp>::__digits);
  }
#else
  template <typename _Tp>
  constexpr _Tp
  __rotl(_Tp __x, int __s) noexcept
  {
    constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
    if _GLIBCXX17_CONSTEXPR ((_Nd & (_Nd - 1)) == 0)
    {
      // Variant for power of two _Nd which the compiler can
      // easily pattern match.
      constexpr unsigned __uNd = _Nd;
      const unsigned __r = __s;
      return (__x << (__r % __uNd)) | (__x >> ((-__r) % __uNd));
    }
    const int __r = __s % _Nd;
    if (__r == 0)
      return __x;
    else if (__r > 0)
      return (__x << __r) | (__x >> ((_Nd - __r) % _Nd));
    else
      return (__x >> -__r) | (__x << ((_Nd + __r) % _Nd)); // rotr(x, -r)
  }
#endif
  template <typename _Tp>
  constexpr _Tp
  __rotr(_Tp __x, int __s) noexcept
  {
    constexpr int _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
    if _GLIBCXX17_CONSTEXPR ((_Nd & (_Nd - 1)) == 0)
    {
      // Variant for power of two _Nd which the compiler can
      // easily pattern match.
      constexpr unsigned __uNd = _Nd;
      const unsigned __r = __s;
      return (__x >> (__r % __uNd)) | (__x << ((-__r) % __uNd));
    }
    const int __r = __s % _Nd;
    if (__r == 0)
      return __x;
    else if (__r > 0)
      return (__x >> __r) | (__x << ((_Nd - __r) % _Nd));
    else
      return (__x << -__r) | (__x >> ((_Nd + __r) % _Nd)); // rotl(x, -r)
  }
#ifdef ARDUINO_ARCH_SAM
  template <typename _Tp>
  constexpr int
  __countl_zero_2(_Tp __x, int _Nd, int _Nd_ull, unsigned long long __high) noexcept
  {
    return __high != 0 ? __builtin_clzll(__high) - (2 * _Nd_ull) - _Nd : (_Nd - _Nd_ull) + __builtin_clzll(__x & __gnu_cxx::__int_traits<unsigned long long>::__max);
  }
  template <typename _Tp>
  constexpr int
  __countl_zero_1(_Tp __x, int _Nd, int _Nd_ull, int _Nd_ul, int _Nd_u) noexcept
  {
    return _Nd <= _Nd_u ? __builtin_clz(__x) - _Nd_u - _Nd : _Nd <= _Nd_ul ? __builtin_clzl(__x) - _Nd_ul - _Nd
                                                         : _Nd <= _Nd_ull  ? __builtin_clzll(__x) - _Nd_ull - _Nd
                                                                           : __countl_zero_2(__x, _Nd, _Nd_ull, __x >> _Nd_ull);
  }
  template <typename _Tp>
  constexpr int
  __countl_zero_0(_Tp __x, int _Nd) noexcept
  {
    using __gnu_cxx::__int_traits;

    return __x == 0 ? _Nd : __countl_zero_1(__x, _Nd, __int_traits<unsigned long long>::__digits, __int_traits<unsigned long>::__digits, __int_traits<unsigned>::__digits);
  }
  template <typename _Tp>
  constexpr int
  __countl_zero(_Tp __x) noexcept
  {
    return __countl_zero_0(__x, __gnu_cxx::__int_traits<_Tp>::__digits);
  }
#else
  template <typename _Tp>
  constexpr int
  __countl_zero(_Tp __x) noexcept
  {
    using __gnu_cxx::__int_traits;
    constexpr auto _Nd = __int_traits<_Tp>::__digits;

    if (__x == 0)
      return _Nd;

    constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
    constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
    constexpr auto _Nd_u = __int_traits<unsigned>::__digits;

    if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
    {
      constexpr int __diff = _Nd_u - _Nd;
      return __builtin_clz(__x) - __diff;
    }
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul)
    {
      constexpr int __diff = _Nd_ul - _Nd;
      return __builtin_clzl(__x) - __diff;
    }
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull)
    {
      constexpr int __diff = _Nd_ull - _Nd;
      return __builtin_clzll(__x) - __diff;
    }
    else // (_Nd > _Nd_ull)
    {
      static_assert(_Nd <= (2 * _Nd_ull),
                    "Maximum supported integer size is 128-bit");

      unsigned long long __high = __x >> _Nd_ull;
      if (__high != 0)
      {
        constexpr int __diff = (2 * _Nd_ull) - _Nd;
        return __builtin_clzll(__high) - __diff;
      }
      constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
      unsigned long long __low = __x & __max_ull;
      return (_Nd - _Nd_ull) + __builtin_clzll(__low);
    }
  }
#endif
  template <typename _Tp>
  constexpr int
  __countl_one(_Tp __x) noexcept
  {
    return std::__countl_zero<_Tp>((_Tp)~__x);
  }

  template <typename _Tp>
  constexpr int
  __countr_zero(_Tp __x) noexcept
  {
    using __gnu_cxx::__int_traits;
    constexpr auto _Nd = __int_traits<_Tp>::__digits;

    if (__x == 0)
      return _Nd;

    constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
    constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
    constexpr auto _Nd_u = __int_traits<unsigned>::__digits;

    if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
      return __builtin_ctz(__x);
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul)
      return __builtin_ctzl(__x);
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull)
      return __builtin_ctzll(__x);
    else // (_Nd > _Nd_ull)
    {
      static_assert(_Nd <= (2 * _Nd_ull),
                    "Maximum supported integer size is 128-bit");

      constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
      unsigned long long __low = __x & __max_ull;
      if (__low != 0)
        return __builtin_ctzll(__low);
      unsigned long long __high = __x >> _Nd_ull;
      return __builtin_ctzll(__high) + _Nd_ull;
    }
  }

  template <typename _Tp>
  constexpr int
  __countr_one(_Tp __x) noexcept
  {
    return std::__countr_zero((_Tp)~__x);
  }

  template <typename _Tp>
  constexpr int
  __popcount(_Tp __x) noexcept
  {
    using __gnu_cxx::__int_traits;
    constexpr auto _Nd = __int_traits<_Tp>::__digits;

    constexpr auto _Nd_ull = __int_traits<unsigned long long>::__digits;
    constexpr auto _Nd_ul = __int_traits<unsigned long>::__digits;
    constexpr auto _Nd_u = __int_traits<unsigned>::__digits;

    if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
      return __builtin_popcount(__x);
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul)
      return __builtin_popcountl(__x);
    else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull)
      return __builtin_popcountll(__x);
    else // (_Nd > _Nd_ull)
    {
      static_assert(_Nd <= (2 * _Nd_ull),
                    "Maximum supported integer size is 128-bit");

      constexpr auto __max_ull = __int_traits<unsigned long long>::__max;
      unsigned long long __low = __x & __max_ull;
      unsigned long long __high = __x >> _Nd_ull;
      return __builtin_popcountll(__low) + __builtin_popcountll(__high);
    }
  }

  template <typename _Tp>
  constexpr bool
  __has_single_bit(_Tp __x) noexcept
  {
    return std::__popcount(__x) == 1;
  }

  template <typename _Tp>
  constexpr _Tp
  __bit_ceil(_Tp __x) noexcept
  {
    using __gnu_cxx::__int_traits;
    constexpr auto _Nd = __int_traits<_Tp>::__digits;
    if (__x == 0 || __x == 1)
      return 1;
    auto __shift_exponent = _Nd - std::__countl_zero((_Tp)(__x - 1u));
    // If the shift exponent equals _Nd then the correct result is not
    // representable as a value of _Tp, and so the result is undefined.
    // Want that undefined behaviour to be detected in constant expressions,
    // by UBSan, and by debug assertions.
    if (!std::__is_constant_evaluated())
    {
      __glibcxx_assert(__shift_exponent != __int_traits<_Tp>::__digits);
    }

    using __promoted_type = decltype(__x << 1);
    if _GLIBCXX17_CONSTEXPR (!is_same<__promoted_type, _Tp>::value)
    {
      // If __x undergoes integral promotion then shifting by _Nd is
      // not undefined. In order to make the shift undefined, so that
      // it is diagnosed in constant expressions and by UBsan, we also
      // need to "promote" the shift exponent to be too large for the
      // promoted type.
      const int __extra_exp = sizeof(__promoted_type) / sizeof(_Tp) / 2;
      __shift_exponent |= (__shift_exponent & _Nd) << __extra_exp;
    }
    return (_Tp)1u << __shift_exponent;
  }

  template <typename _Tp>
  constexpr _Tp
  __bit_floor(_Tp __x) noexcept
  {
    constexpr auto _Nd = __gnu_cxx::__int_traits<_Tp>::__digits;
    if (__x == 0)
      return 0;
    return (_Tp)1u << (_Nd - std::__countl_zero((_Tp)(__x >> 1)));
  }

  template <typename _Tp>
  constexpr int
  __bit_width(_Tp __x) noexcept
  {
    return __gnu_cxx::__int_traits<_Tp>::__digits - std::__countl_zero(__x);
  }

  /// @endcond

#ifdef __cpp_lib_bitops // C++ >= 20
#ifdef __cpp_concepts
  /// @cond undocumented
  template <typename _Tp>
  concept __unsigned_integer = __is_unsigned_integer<_Tp>::value;
/// @endcond
#else
#define __unsigned_integer typename
#endif
  // [bit.rot], rotating

  /// Rotate `x` to the left by `s` bits.
  template <__unsigned_integer _Tp>
  [[nodiscard]] constexpr _Tp
  rotl(_Tp __x, int __s) noexcept
  {
    return std::__rotl(__x, __s);
  }

  /// Rotate `x` to the right by `s` bits.
  template <__unsigned_integer _Tp>
  [[nodiscard]] constexpr _Tp
  rotr(_Tp __x, int __s) noexcept
  {
    return std::__rotr(__x, __s);
  }

  // [bit.count], counting

  /// The number of contiguous zero bits, starting from the highest bit.
  template <__unsigned_integer _Tp>
  constexpr int
  countl_zero(_Tp __x) noexcept
  {
    return std::__countl_zero(__x);
  }

  /// The number of contiguous one bits, starting from the highest bit.
  template <__unsigned_integer _Tp>
  constexpr int
  countl_one(_Tp __x) noexcept
  {
    return std::__countl_one(__x);
  }

  /// The number of contiguous zero bits, starting from the lowest bit.
  template <__unsigned_integer _Tp>
  constexpr int
  countr_zero(_Tp __x) noexcept
  {
    return std::__countr_zero(__x);
  }

  /// The number of contiguous one bits, starting from the lowest bit.
  template <__unsigned_integer _Tp>
  constexpr int
  countr_one(_Tp __x) noexcept
  {
    return std::__countr_one(__x);
  }

  /// The number of bits set in `x`.
  template <__unsigned_integer _Tp>
  constexpr int
  popcount(_Tp __x) noexcept
  {
    return std::__popcount(__x);
  }
#endif // __cpp_lib_bitops

#ifdef __cpp_lib_int_pow2 // C++ >= 20
  // [bit.pow.two], integral powers of 2

  /// True if `x` is a power of two, false otherwise.
  template <__unsigned_integer _Tp>
  constexpr bool
  has_single_bit(_Tp __x) noexcept
  {
    return std::__has_single_bit(__x);
  }

  /// The smallest power-of-two not less than `x`.
  template <__unsigned_integer _Tp>
  constexpr _Tp
  bit_ceil(_Tp __x) noexcept
  {
    return std::__bit_ceil(__x);
  }

  /// The largest power-of-two not greater than `x`.
  template <__unsigned_integer _Tp>
  constexpr _Tp
  bit_floor(_Tp __x) noexcept
  {
    return std::__bit_floor(__x);
  }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // 3656. Inconsistent bit operations returning a count
  /// The smallest integer greater than the base-2 logarithm of `x`.
  template <__unsigned_integer _Tp>
  constexpr int
  bit_width(_Tp __x) noexcept
  {
    return std::__bit_width(__x);
  }
#endif // defined (__cpp_lib_int_pow2)

#ifdef __cpp_lib_endian // C++ >= 20

  /// Byte order constants
  /**
   * The platform endianness can be checked by comparing `std::endian::native`
   * to one of `std::endian::big` or `std::endian::little`.
   *
   * @since C++20
   */
  enum class endian
  {
    little = __ORDER_LITTLE_ENDIAN__,
    big = __ORDER_BIG_ENDIAN__,
    native = __BYTE_ORDER__
  };
#endif // __cpp_lib_endian

  /// @}

  _GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#endif // C++14
#endif // _GLIBCXX_BIT